The use of a ball joint trailer coupling comprising a hitch ball and cooperating socket assembly to tow a trailer behind a towing vehicle is generally known. Such ball joint couplings often comprise a hitch ball and corresponding hitch ball receiver. The ball joint coupling provides the necessary freedom of movement to allow a trailer to track smoothly behind the towing vehicle while also providing a dependable connection. One example of a hitch ball design is set forth in U.S. Pat. No. 6,983,950 to McCoy et al., which is hereby incorporated by reference in its entirety.
Towed vehicles, such as trailers, may experience turbulence and other forces that cause them to sway, fishtail or otherwise veer from the route directed from the towing vehicle. In particular, hitches such as ball joint hitches allow a large degree of travel and lateral movement of the towed vehicle with respect to the direction of the towing vehicle. Too much sway, however, may have dangerous and even catastrophic effects. For example, a fishtailing towed vehicle may tip or roll over.
To prevent such undesired effect it may be useful to monitor the direction of travel of the towed vehicle with respect to the towing vehicle. Accordingly, a sensor designed to monitor the angular direction of travel of a towed vehicle is needed.